What's the point of "field point"?

There are the simple conical target points, that are used for "serious" target shooting, so their at least as accurate as FP. And AFAIK, the TP are intended forreduced penetration which is good for practice sessions.

So what is the purpose of field point and their elaborate shape? What is the meaning of the "FIELD" part of the name?

In crossbows forum someone thought TP where prohibited in the sixties for one of the NFAA classes. But it doesnt explain why FPs are widely used today.

Any idea? do YOU use FP? why?